Wireless Communication System Utilizing Enhanced Air-Interface

ABSTRACT

In a Long Term Evolution (LTE) environment, the LTE network can coordinate with a subscribing user equipment to manage offloading to a wireless local area network (WLAN) access point or other base station. In doing so, the serving base station on the LTE network can acquire device capabilities of the user equipment and provide configuration details to the user equipment based on those capabilities. These configuration details may cause the user equipment to monitor one or more triggers, and may configure a scan to be later performed by the user equipment. Based on the monitored trigger, the user equipment can then scan the environment according to the scan configuration defined by the base station, and relay scan results to the base station to make a handover determination.

CROSS-REFERENCED TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication No. 61/753,749, filed Jan. 17, 2013, entitled “WirelessCommunication System Utilizing Enhanced Air-Interface,” which isincorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

This disclosure relates to offloading communications traffic from a basestation, for example, to one or more WLAN access points within acommunications environment.

2. Related Art

Wireless communication devices, such as cellular telephones to providean example, have become commonplace in both personal and commercialsettings. The wireless communication devices provide users with accessto all kinds of information. For example, a user can access the internetthrough an internet browser on the device, download miniatureapplications (e.g., “apps”) from a digital marketplace, send and receiveemails, or make telephone calls using a voice over internet protocol(VoIP). Consequently, wireless communication devices provide users withsignificant mobility, while allowing them to remain “connected” tocommunication channels and information.

Wireless communication devices communicate with one or more otherwireless communication devices or wireless access points to send andreceive data. Typically, the wireless communication device willcontinuously detect and measure connection characteristics in order tomake a determination as to whether it should remain connected to acurrent base station, or switch to a different base station. Also, whena determination has been made to offload, conventional wirelesscommunication systems use unicast signaling to communicate offloadtriggers and configurations between a User Equipment (UE) and a network.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

Embodiments of the disclosure are described with reference to theaccompanying drawings. In the drawings, like reference numbers indicateidentical or functionally similar elements. Additionally, the left mostdigit(s) of a reference number identifies the drawing in which thereference number first appears.

FIG. 1 illustrates a diagram of an exemplary wireless communicationenvironment;

FIG. 2 illustrates a block diagram of an exemplary base station andaccess point within an exemplary wireless communication environment;

FIG. 3 illustrates a block diagram of an exemplary base station;

FIG. 4 illustrates a block diagram of an exemplary user equipment;

FIG. 5 illustrates a flowchart diagram of an exemplary handoverprocedure according to an embodiment;

FIG. 6 illustrates a flowchart diagram of an exemplary handoverprocedure according to an embodiment;

FIG. 7 illustrates a flowchart diagram of an exemplary handoverprocedure according to an embodiment;

FIG. 8 illustrates a flowchart diagram of an exemplary handoverprocedure according to an embodiment; and

FIG. 9 illustrates a block diagram of a general purpose computer.

The disclosure will now be described with reference to the accompanyingdrawings. In the drawings, like reference numbers generally indicateidentical, functionally similar, and/or structurally similar elements.The drawing in which an element first appears is indicated by theleftmost digit(s) in the reference number.

DETAILED DESCRIPTION

The following Detailed Description of the present disclosure refers tothe accompanying drawings that illustrate exemplary embodimentsconsistent with this disclosure. The exemplary embodiments will so fullyreveal the general nature of the disclosure that others can, by applyingknowledge of those skilled in relevant art(s), readily modify and/oradapt for various applications such exemplary embodiments, without undueexperimentation, without departing from the spirit and scope of thedisclosure. Therefore, such adaptations and modifications are intendedto be within the meaning and plurality of equivalents of the exemplaryembodiments based upon the teaching and guidance presented herein. It isto be understood that the phraseology or terminology herein is for thepurpose of description and not of limitation, such that the terminologyor phraseology of the present specification is to be interpreted bythose skilled in relevant art(s) in light of the teachings herein.Therefore, the detailed description is not meant to limit the presentdisclosure.

The embodiment(s) described, and references in the specification to “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment(s) described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is understood that it iswithin the knowledge of one skilled in the art to effect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described.

Embodiments of the disclosure may be implemented in hardware, firmware,software, or any combination thereof. Embodiments of the disclosure mayalso be implemented as instructions stored on a machine-readable medium,which may be read and executed by one or more processors. Amachine-readable medium may include any mechanism for storing ortransmitting information in a form readable by a machine (e.g., acomputing device). For example, a machine-readable medium may includeread only memory (ROM); random access memory (RAM); magnetic diskstorage media; optical storage media; flash memory devices. Further,firmware, software, routines, instructions may be described herein asperforming certain actions. However, it should be appreciated that suchdescriptions are merely for convenience and that such actions in factresult from computing devices, processors, controllers, or other devicesexecuting the firmware, software, routines, instructions, etc.

For purposes of this discussion, the term “module” and the like, shallbe understood to include at least one of software, firmware, andhardware (such as one or more circuits, microchips, processors, ordevices, or any combination thereof), and any combination thereof. Inaddition, it will be understood that each module can include one, ormore than one, component within an actual device, and each componentthat forms a part of the described module can function eithercooperatively or independently of any other component forming a part ofthe module. Conversely, multiple modules described herein can representa single component within an actual device. Further, components within amodule can be in a single device or distributed among multiple devicesin a wired or wireless manner.

Terms like “user equipment,” “mobile station,” “mobile,” “mobiledevice,” “subscriber station,” “subscriber equipment,” “accessterminal,” “terminal.” “handset,” and similar terminology, refer to awireless device utilized by a subscriber or user of a wirelesscommunication service to receive or convey data, control, voice, video,sound, gaming, or substantially any data-stream or signaling-stream. Theforegoing terms may be utilized interchangeably in the subjectspecification and related drawings. Likewise, the terms “access point,”“base station,” “base transceiver station”, “Node B.” “evolved Node B(eNode B),” home Node B (HNB),” “home access point (NAP),” or the like,may be utilized interchangeably in the subject specification anddrawings, and refer to a wireless network component or apparatus thatserves and receives data, control, voice, video, sound, gaming, orsubstantially any data-stream or signaling-stream from a set ofsubscriber stations.

Although several portions of the description of the present disclosuremay be described in terms of wireless devices (specifically cellulardevices), those skilled in the relevant art(s) will recognize that thepresent disclosure may be applicable to any other devices withoutdeparting from the spirit and scope of the present disclosure.

An Exemplary Wireless Communication Environment

FIG. 1 illustrates an exemplary wireless communication environment 100.In the environment 100, there may be included one or more base stations,such as base stations 110 and 120. Although the base stations may betermed differently in the art depending on their corresponding radioaccess technology (e.g., eNodeB for 4G, etc.), for purposes of thisdisclosure they will collectively be referred to as “base stations.” Inaddition to the base stations, the environment 100 may also include oneor more WLAN access points, such as access points 165, 175, 185 and 195.

In the environment 100, a user equipment (UE) 150 connects to one of thebase stations (e.g., base station 120). As discussed above,conventionally, while the UE 150 is connected to the base station 120,the UE will continuously measure connection characteristics of theserving base station 120, as well as other nearby base stations (e.g.,base station 110). From the characteristics, the UE 150 can makedeterminations as to whether to offload from the serving base station120 to the nearby base station 110.

Today's wireless communication devices (e.g., UEs) have the ability toaccess the internet, stream video and music, and other such activitiesthat can cause significant congestion in mobile cellular networks.Therefore, inter-system offloading has been devised as a potentialsolution, which causes the UE to offload from a serving base station toa different radio access technology (RAT), such as WLAN (e.g., via aWLAN access point). This can not only assist with alleviating cellcongestion, but can also provide the user with better quality of serviceand user experience. WLAN may also be known as WiFi, and therefore WiFiand WLAN are interchangeable herein. In an embodiment, WiFi can be anyWLAN compatible with one or more the IEEE 802.11 suite of standards.

Conventional offloading solutions, such as 3GPP I-WLAN architecture (See3GPP TS 23.234 specification, incorporated herein by reference in itsentirety), relies on policies stored in the UE with pre-configuredconditions to trigger offloading and controlled by Access NetworkDiscovery and Selection Function (ANDSF). The ANDSF framework uses thesepolicies to assist user devices to discover access networks in theirvicinity and prioritize/manage connections to all networks. Thesepolicies are either statically pre-configured on the UE or dynamicallyupdated by the ANDSF network element to the UE via Open Mobile AllianceDevice Management protocol, i.e. OMA DM protocol.

When a certain policy becomes “active”, e.g. the UE moves close to acell that is specified in the policy validity condition, the UE notifiesthe event to the ANDSF server and requests the Inter-system discoveryinformation based on the preferred access technology recommended in thepolicy, e.g. WLAN. The ANDSF server will provide the UE with Wi-FiHotspot service set identifier (e.g. access point SSIDs) in the vicinityand related Wi-Fi access information such as security keys. The UE usesthese assistance data to connect to the Wi-Fi network.

There are a several drawbacks with this approach. For example, the ANDSFframework stores the policies in the UE and relies on OMA DM protocol toupdate policies. Since the OMA DM protocol is slow, it is not responsiveenough to support network-based interworking trigger events, such asoffload due to sudden overload on Long Term Evolution (LTE) eNodeBs.Also, the types of triggers or validity conditions are limited. Onlylocation, time-of-day, or types of application are available in 3GPPRel-11 specification. Further, the information provided to the UE forWi-Fi discovery and selection is also very limited. Further still, thisconfiguration lacks the capability for the UE to provide up-to-dateradio resource information at the offload side to the cellular network.

Therefore, in an embodiment, the UE can communicate its capabilities tothe base station. Based on these capabilities, the base station candefine and notify the UE of triggering conditions that will cause the UEto scan. During operation, the UE can then be configured to providecertain status updates to the base station, which the base station canfactor into its offload decision-making. Based on the defined triggeringconditions, the UE can scan the environment and report back to the basestation for cooperatively determining whether to handoff. This approachwill be discussed in more detail throughout the present specification.

FIG. 2 illustrates a block diagram of an exemplary base station 210 andWLAN access point 230. In an embodiment, the base station 210 and theWLAN access point 230 can be connected by a host 220. The host 220 canperform coordinated control of the base station 210 and the WLAN accesspoint 230, and/or represent a communication link between the basestation 210 and the access point 230. In this configuration, the basestation 210 can acquire information from the access point 230 to assistwith the offloading decision-making and/or scanning instruction providedto the UE.

Exemplary Base Station and User Equipment

FIG. 3 illustrates a block diagram of an exemplary base station 300. Thebase station 300 includes a communication module 310, a capabilitymodule 320, a notification module 330, an access point storage module340, and a trigger module 350, all or some of which can be executedutilizing one or more processors or circuits. For example, all or someof the modules of base station 300 can be implemented using one or moreprocessor(s) and/or state machine logic and/or circuits, or acombination thereof, programmed or implemented to have the functionalitydescribed herein. Although separate modules are illustrated in FIG. 3,the disclosure is not so limited, as will be understood by those skilledin the arts. The modules can be combined in one or more modules, and canbe implemented by software, hardware, or a combination thereof. The basestation 300 may represent an exemplary embodiment of the base station110 within the wireless communication environment 100.

The communication module 310 includes a radio 312 that is configured tocommunicate with UEs, base stations, and/or access points in theenvironment 100. The communication module 310 acquires data from theother devices in the environment 100 for use in the offloadingdetermination and configuration, and can issue offloading triggersand/or commands to UEs in the environment 100, as will be discussed infurther detail below.

FIG. 4 illustrates a block diagram of an exemplary user equipment (UE)(e.g., wireless communication device) 400 according to an embodiment.The UE 400 includes a communication module 410, a capability module 420,a location module 430, a trigger monitoring module 440, a scan module450, and a trigger module 460, all of which can be executed utilizingone or more processors. For example, all or some of the modules of UE400 can be implemented using one or more processor(s) and/or statemachine logic and/or circuits, or a combination thereof, programmed orimplemented to have the functionality described herein. Althoughseparate modules are illustrated in FIG. 4, the disclosure is not solimited, as will be understood by those skilled in the arts. The modulescan be combined in one or more modules, and can be implemented bysoftware, hardware, or a combination thereof. The UE 400 may representan exemplary embodiment of the UE 150 within the wireless communicationenvironment 100.

Offloading Coordination

While the UE 400 is being served by the base station 300, the basestation can coordinate with the UE 400 in order to configure variousoffloading procedures for streamlining future offloading from the basestation 300 to a WLAN or other access point. In an embodiment, the basestation 300 operates according to a first RAT, e.g. a cellular carrierstandard, such as LTE, 4G, 3G, among others. Accordingly, thecommunication module 410 includes a first radio 412 having a transmitterand receiver for effecting the cellular communications with the basestation 300. Further, the communication module 410 includes a secondradio 414 having a transmitter and receiver for effecting communicationswith the offload technology that is a different RAT from the cellularRAT, e.g. WLAN.

WLAN Interworking Exchange

At the outset, in order to configure the offloading, the base station300 should first acquire the various capabilities of the UE 400 as theyrelate to offloading. Therefore, the capability module 320 of the basestation 300 transmits a WLAN interworking capability inquiry message tothe UE 400 via the radio 312 of the communication module 310. The WLANinterworking capability inquiry message requests the UE 400 to respondwith its WLAN and other communication abilities, as well as whetherother pertinent offloading capabilities, as will be discussed herein. AUECapabilityEnquiry message, which is defined as part of the “UEcapability transfer” procedure of the LTE standard, is modifiedaccording to embodiments herein to include the WLAN interworkingcapability inquiry message. Herein, standards related messages,including existing, modified or new per the disclosure herein, areitalicized, for ease of understanding.

The UE 400 receives this message via its own radio 412 included in itscommunication module 410 and forwards the message to the capabilitymodule 420. The capability module 420 is responsible for assessing thecurrent capabilities of the UE 400 and providing a response to the WLANinterworking capability inquiry message that includes the requestedcapabilities. In an embodiment, the capabilities can be programmedduring manufacturing and are known by the capability module 420. Inanother embodiment, the capability module 420 can perform a diagnosticperiodically or at the time of receiving the WLAN interworkingcapability inquiry message in order to determine whether one or more ofits original capabilities are in working order so as to provide a moreaccurate response to the base station 300. The capabilities can includean indication of the one or more versions of the IEEE 802.11x standardsthat the UE is compatible with, including IEEE 802.11a, 802.11b,802.11g, 802.11n, etc.

After the capability module 420 has determined the availablecapabilities of the UE 400, the capability module 420 responds to thebase station 300 with a WLAN interworking capability informationmessage. This message will preferably include an indication regardingwhether the UE 400 is capable of performing WLAN interworking mobilityprocedures. For purposes of this discussion, WLAN interworking mobilityprocedures include the ability to receive commands from the cellularnetwork (such as LTE, for example) to be applied to a connection betweenthe UE and WLAN or another divergent network and/or access point. TheWLAN interworking capability information message can include additionalinformation that may be pertinent to the offloading procedure, or asrequested by the base station 300, such as for example the WLAN radiocapability (e.g., WLAN frequency bands, data rates, etc.) of the UE 400.

In addition to the interworking and WLAN radio capabilities, thecapability module 420 may also include relevant device restrictions thatshould be accounted for by the base station 300. For example, thecapability module 420 can include an indication as to whether the UErequires measurement gaps to perform scanning. For purposes of thisdiscussion, a measurement gap is a period downlink silence, during whichthe UE 400 can perform a radio scan of its environment. In other words,the measurement gap is a period of time provided to the UE 400 by thebase station 300 during which the base station 300 will refrain fromtransmitting data to the UE 400. In addition to the measurement gapinformation, the capability module 420 may also prompt the triggermodule 460 for proposed triggers, and may then include any such proposedtriggers in the WLAN interworking capability information message. Theproposing of the triggers will be discussed in further detail below.

To summarize, in response to the WLAN interworking capability inquirymessage received from the base station 300, the capability module canrespond with a WLAN interworking capability information message thatincludes: (1) whether WLAN interworking supported or not supported; (2)whether WLAN measurement gap needed or not needed; (3) (Optionally) theWLAN radio capabilities including IEEE 802.11 compatible standards; and(4) (Optionally) Proposed WLAN interworking notification triggerconditions. Additional information can be included in the responsemessage that may be pertinent or requested, within the spirit and scopeof the present disclosure.

In an embodiment, the base station 300 might need to forward the WLANinterworking capabilities (or other information) of the UE 400 to otherentities in the core network. One possible solution is for the basestation 300 to share this information with a network backhaul, such as aMobility Management Entity (MME), for providing to other base stationsin the environment 100. In addition, the base station 300 can also sharethis information directly with other eNodeBs. Alternatively, the MME canacquire the WLAN interworking capabilities using dedicated signaling,such as NAS signaling (See 3GPP TS 24.301 specification, incorporatedherein by reference in its entirety). The MME can then distribute theacquired information to the relevant base stations, such as base station300. This procedure may include a determination by the MME as to whetherthe base station 300 should be aware of the acquired information, or arequest to the MME by the base station 300. In an embodiment, the MMEmay also make a determination as to whether there is a “mismatch” inorder to prevent forwarding the WLAN interworking capabilities to a basestation that is not capable of WLAN interworking procedures.

WLAN Interworking Notification and Configuration

Once the base station 300 has received the capability information fromthe user equipment 400, the base station 300 can then proceed toconfigure the notification procedure that will be carried out by thebase station 300 and the user equipment 400. The notification proceduredefines how the user equipment 400 or the base station 300 can triggerinterworking assistance for scanning and/or offloading the userequipment 400 to a WLAN or other access point (AP).

As discussed above, in an embodiment, the trigger module 460 of the userequipment may respond to the WLAN interworking capability inquirymessage with one or more proposed triggers. These triggers may beparameters that the user equipment 400 is capable of monitoring and/ordetecting, and which could be relevant to deciding whether to offload toa WLAN AP. For example, such proposed triggers may include remainingbattery life, application type, LTE signal strength, among others. Theuse of these triggers by the UE will be discussed in further detailbelow.

The proposed triggers are received by the base station 300 as part ofthe received WLAN interworking capability information message and aresent to the trigger module 350. The trigger module 350 makes adetermination as to whether to accept or reject each of the proposedtriggers, and can also mandate new triggers that were not proposed.These determinations can be made based on the analysis capabilities ofthe base station 300, or preprogrammed or trigger preferences. Thetrigger module 350 can also consult with other eNodeBs and/or othernetwork backhaul entities, e.g. MME, for these determinations. Thetrigger module 350 also has the option of modifying the proposed triggerconditions, such as by their thresholds or other parameters.

Once the trigger module 350 has made its determinations as to thetrigger conditions that should be employed by the UE 400, the triggermodule 350 causes the notification module 330 to transmit a WLANInterworking notification configuration message to the UE 400. The WLANInterworking notification configuration message includes an indicationof whether each of the proposed triggers were accepted, rejected, ormodified, as well as a detailed listing of the additional triggerconditions that should be monitored by the UE 400. In order to compareWLAN Interworking capability message and the WLAN Interworkingnotification configuration message regarding the exchange of triggers,Table 1 below, provides some examples of trigger conditions includedwithin the different messages:

TABLE 1 Example Content of Trigger Conditions in WLAN Messages Use caseWLAN interworking WLAN Interworking capability message notificationconfiguration (UE−>BS) message (BS−>UE) Manual notification “causecodes” for manual Allow/not allow, allowed triggers “cause codes” formanual triggers Battery level Battery threshold (%) to Allow/not allow,battery trigger WLAN threshold (%) setting if interworking notificationallow Type of application TCP/IP port number Allow/not allow, TCP/IPport number if allow . . .

In addition to the triggers, the notification module 330 can alsoinclude within the WLAN Interworking notification configuration messagean indication regarding whether UE notification and WLAN interworkingnotification will be employed for the UE 400. For purposes of thisdiscussion, it will be understood that “UE notification” is the processof the UE 400 automatically detecting whether the triggers have beenmet, performing a environment scan (measurement) upon the satisfactionof one of the triggers, and providing a measurement report to the basestation 300 for determining whether to offload. Herein, scan refers tofrequency tuning the radio 414 in UE 400 to detect potential WLAN accesspoints for offload, including measuring signal strengths atcorresponding frequencies of the access points for inclusion in themeasurement report. It will also be understood that the “WLANinterworking notification” is the process of the UE 400 detectingwhether a trigger has been satisfied, and notifying the base station inthis regard. In response, the base station 300 can then command the UE400 as to whether and what to scan and measure. Further, the basestation 300 can also provide the UE 400 with a prohibit timer thatdefines the minimum amount of time that must elapse between notificationor measurement messages from the UE 400 to the base station 300.

The signaling procedure between the base station 300 and the UE 400 forperforming environment measurement scans will thus depend on which ofthe above features have been enabled by the base station.

In a first scenario, the base station 300 indicates in the WLANNotification Configuration message that both WLAN interworkingnotification and UE notification are allowed.

In this scenario, the UE 400 receives the WLAN NotificationConfiguration message and configures its trigger monitoring module 440to monitor the triggers defined in the message. As part of the WLANinterworking notification, when the trigger monitoring module 440detects that one of the defined triggers has been met, the triggermonitoring module 440 can cause a WLAN Interworking Notification messageto be sent to the base station 300 that includes a notification of thetrigger that has been satisfied. Optionally, the WLAN InterworkingNotification message can also include the location of the UE 400 fromthe location module 430, and/or its accuracy. The location informationcan be used by the base station when configuring the scan parameters ofthe UE 400, as discussed in further detail below.

In a second scenario, the base station 300 indicates in the WLANNotification Configuration message that WLAN interworking notificationis not allowed, but that UE notification is allowed.

In this scenario, because WLAN Notification Configuration is notallowed, the UE 400 does not notify the base station 300 when a triggerhas been satisfied. However, because UE Notification is still allowed,the UE 400 can perform scans of the environment (in accordance with scanparameters set forth by the base station 300, discussed below), andreport the scan results to the base station 300.

In a third scenario, the base station 300 indicates in the WLANNotification Configuration message that neither WLAN interworkingnotification or UE notification is allowed. In an embodiment, the basestation can signal this scenario to the UE 400 by rejecting all proposedtriggers and by not providing any new triggers.

Regardless of the scenario chosen, the base station 300 may at any timereconfigure the UE 400 by transmitting an updated WLAN InterworkingNotification Configuration message. In an embodiment, the UE 400 isconfigured to always follow the latest configuration from the basestation 300.

To summarize the above discussion, the WLAN Interworking NotificationConfiguration message sent by the base station 300 to the UE 400 caninclude: (1) UE notification allowed/disallowed; (2) (Optionally)triggers; (3) (Optionally) prohibit timer; and (Optionally) WLANchannels and AP white/blacklist (discussed below). Similarly, the WLANInternetworking Notification message sent by the UE 400 to the basestation 300 can include: (1) an interworking assistance request; (2)(Optionally) UE location information and estimated accuracy; and(Optionally) preferred technology (e.g., WLAN, WiMAX, etc.) andpreferred network provider.

WLAN Measurement Configuration

Once the scanning and triggering parameters have been configured betweenthe base station 300 and the UE 400, the notification module 330 of thebase station 300 can transmit a WLAN Measurement Configuration messageto configure the scanning parameters that the UE 400 will use whenperforming scans of the environment 100. The parameters can include theWLAN channels that the UE 400 should scan, the triggers that will causethe scan, among others. The scan is intended to gather knowledge ofradio resources at the offload side. The base station 300 can then usethese resources to minimize offload latency by coordinate inter-systemmobility.

In an embodiment, the notification module 330 can generate and forwardthe WLAN Measurement Configuration message anytime after receiving theWLAN Interworking Capability Information message from the UE 400. Inother embodiments, depending on the abilities of the UE 400, thenotification module 330 can transmit the WLAN Measurement Configurationmessage after receiving the WLAN Interworking Notification message(scenario 1), or after one or more triggers are detected by the basestation 300 (scenarios 2 and 3).

In one example, the base station 300 can seek a one-time snapshot of theWLAN APs within the vicinity of the UE 400. This may occur when thenetwork is facing some congestion on air interface capacity or if the UE400 notifies the base station 300 that it needs immediate offloadassistance. Based on the approximate knowledge of the location of the UE400, the notification module 330 can select the WLAN channels that arelikely to have interworking capable WLAN APs in the vicinity of the UE400. The notification module 330 can acquire this information from theaccess point storage module 340, which may store location, frequencychannels, security information, interworking capabilities,owner/operator, and/or other information of the various access pointsthat have been detected or reported in the environment 100. In the aboveexample, the notification module 330 provides the WLAN measurementconfiguration message to the UE 400 notifying it of WLAN APs within itsvicinity to scan. In an embodiment, the notification module 330 cannotify the UE 400 to scan all WLAN channels in its vicinity. This canoccur when the access point storage module 340 does not include anyinformation of APs within the vicinity of the UE 400, or thenotification module 330 does not know the location of the UE 400.

In another embodiment, the notification module 330 can include one ormore scan triggers in the WLAN Measurement Configuration message, whichwill cause the UE 400 to perform the scan only upon the satisfaction ofone or multiple of the triggers. If the message includes both thetriggers and the WLAN channels, the UE will be configured to scan onlythe identified channels and only upon the satisfaction of the triggers.An example of a scan trigger may be the signal strength of the servingbase station. Such a trigger is useful when the offload decision istriggered because of coverage, i.e. network would like tooffload/handover UE to WLAN when LTE signal strength is weak at thecurrent UE location, for example weaker than a predetermined threshold.The signal strength trigger threshold can also be a combination of LTEserving cell, LTE neighboring cells, and WLAN neighbor APs, amongothers. Herein, the triggers in the TI/LAN Measurement Configurationmessage can be referred to as report triggers, as they can cause areport to be generated by the UE.

In another embodiment, the notification module 330 can include a scanperiodicity and/or a maximum report amount in the WLAN MeasurementConfiguration message. The scan periodicity defines the intervals withwhich the UE 400 will repeatedly perform the scanning operation. Thisconfiguration may be beneficial if the network detects the UE 400 is ina medium mobility state and the UE may require WLAN offload/handoversoon. As with the above, the scan periodicity can be included with oneor both of the WLAN channels and the triggers for a combinedconfiguration. The maximum report amount, on the other hand, identifiesa maximum number of APs that the UE 400 should report back from itsscan.

In any scenario, the notification module 330 can limit its listing ofaccess points to those that it doesn't expect to be subject to LTE/WLANinterference. In addition, the notification module 330 can alsoconfigure measurement gaps for the UE 400 based on whether the UEindicated in the WLAN Interworking Capability message that it requiresmeasurement gaps.

In an embodiment, the notification module 330 can also include in theWLAN Measurement Configuration message an AP whitelist or blacklist inthe form of WLAN SSIDs. The whitelist identifies APs that the UE 400should precede to report, whereas the blacklist identifies APs that theUE should not report. In an embodiment, the whitelist can identify onlythe APs that are owned by (or associated with) the operator/owner of thebase station 300. Similarly, the blacklist can identify the APs that arenot owned by (or associated with) the operator/owner of the base station300.

In an embodiment, the notification module 330 can also include in theWLAN Measurement Configuration message a request for the UE to providelocation information of itself and/or the measured APs in its responseto the message.

To summarize the above, the base station provides the following contentin the WLAN measurement configuration message: (1) the WLAN channels toscan; (2) report trigger: one-shot, threshold-based, or periodic; (3)(Optionally) report periodicity and maximum report quantity; (4)(Optionally) the SSID whitelist (and corresponding “SSID label”) and/orblacklist; and (5) (Optionally) location information request inmeasurement reports (See e.g., “WLAN Measurements for SON Purpose,”below).

Once the base station 300 has generated and transmitted the WLANmeasurement configuration message to the UE 400, the UE 400 receives themessage at its scan module 450. Using the parameters contained withinthe message, the UE 400 configures the scan module 450 accordingly. Atthe prescribed time, the scan module 450 scans the environment inaccordance with its configuration and stores information relating to thedetected WLAN access points.

To provide an example, if the scan is to be performed upon a trigger,the trigger monitoring module 440 notifies the scan module 450 when thetrigger has been satisfied. This causes the scan module 450 to tune theradio 414 for WLAN to scan the environment at the channels/frequenciesidentified by the base station 300. The scanning can measure signalstrengths at various frequencies and other information indicated belowin the measurement report. For example, SSIDs and data load can bedetermined from beacons transmitted by the various APs. In anembodiment, the scan module 450 is capable of scanning both APs withbroadcast SSIDs and those with hidden SSIDs. In order to determineinformation of APs with hidden SSIDs, the scan module 450 may beconfigured to actively scan those APs (as opposed to the passive scan ofthe other APs).

After the scan, the scan module 450 generates a WLAN measurement reportto inform the base station 300 of the scan results. In an embodiment,the report includes signal strength, BSSID, SSID, as well as otherbroadcast fields, such as AP load (See IEEE 802.11-2012, IEEE Standardfor Information technology—Telecommunications and information exchangebetween systems Local and metropolitan area networks—Specificrequirements Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) Specifications, incorporated herein by reference inits entirety), HESSID, “Roaming Consortium” (See 802.11u-2011—IEEEStandard for Information Technology-Telecommunications and informationexchange between systems-Local and Metropolitan networks-specificrequirements-Part II: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) specifications: Amendment 9: Interworking withExternal Networks, incorporated herein by reference in its entirety),and any vendor specific fields, the UE should be able to report them aswell.

If the received WLAN measurement configuration message included awhitelist (e.g. approved) or blacklist (e.g. disapproved), the scanmodule 450 generates the WLAN measurement report to only include theinformation of the APs that satisfy the white/blacklist.

To summarize the above, the scan module 450 generates and transmits theWLAN measurement report to include: (1) signal strength, BSSID, and/orSSID; and (2) (Optionally) BSS load, HESSID, “Roaming Consortium,” andany vendor specific fields from the WLAN beacon.

WLAN Measurement Information for Self-Optimization

Self-configuring and self-optimizing network (SON) is a feature that canbe used to reduce operational efforts and complexity for mobile wirelessnetworks. In the early deployment phase, the efforts to set up andoptimize were significant and traditionally lead to lengthy periods ofgetting an optimum and stable system setup. One SON scenario configuresand instructs each UE to perform measurements on the radio resources inits vicinity and the network can use such information to discoverneighbor cells and/or optimize the network configurations. Here, thisconcept is extended to wireless inter-system networks, e.g. for thenetwork to discover offload WLAN APs in the deployments, by using. WLANmeasurement configuration message and WLAN measurement report messageand related procedures.

If the network knows the UE is able to provide location information(e.g. through prior UE capability exchanges), the network may optionallyrequest the UEs to append location information by setting a flag in WLANmeasurement configuration message. Upon receiving such request, the UEshall append location information, whenever such information isavailable, for each BSSID discovered when they report measurementresults in the WLAN measurement report message.

To summarize, the network optionally adds, in the WLAN measurementconfiguration message, request location information in measurementreports. Additionally, the UE can optionally provide, in the WLANmeasurement report together with the existing contents described above(See e.g., “WLAN Measurement Configuration”), location information wherethe corresponding BSSID is discovered.

WLAN Handover Command

After the base station 300 receives the WLAN measurement report from theUE 400, the base station 300 forwards the received report to thehandover module 360. Based on the information contained in the report,the handover module 360 makes a determination as to whether the UE 400should offload to a WLAN AP or other base station, and notifies the UE400 accordingly. The handover module 360 can cause the notificationmodule 330 to issue a WLAN handover command message upon determiningthat a handover is needed. The WLAN handover command notifies the UE 400to perform a handover to an AP identified in the command message. The APcan be identified by its BSSID, or by another method, as will bedescribed in further detail below.

In the WLAN handover command, the handover module 360 can optionallyinclude WLAN security parameters and credentials so as to expedite thesecurity procedures to take place between the UE 400 and the WLAN Accesspoint. The handover module 360 can acquire this information via the host220. When pre-authentication is available, the handover module 360 canalso provide pre-authentication WLAN credentials. On the other hand,when pre-authentication is not available, the handover module 360 canoptionally provide one or more of the following security parametersrelating to the WLAN AP: (1) WLAN security mode: WEP, 802.1X, WPA,WPA-PSK, WPA2, WPA2-PSK; and/or (2) EAP authentication methods: EAP-MD5,EAP-OTP, EAP-GTC, EAP-TLS, EAP-TTLS, EAP-IKEv2, EAP-SIM, EAP-AKA.

In an embodiment, the handover module 360 may determine that a handoveris needed without the WLAN measurement configuration and reportprocedures having been completed or configured. For purposes of thisdiscussion, this procedure will be referred to as a “blind handover.” Inthe blind handover embodiment, the handover module 360 preferably knowsthe location of the UE and has confidence that the UE 400 can attach toa specific AP with good success. For example, the UE notificationmessage can indicate the UE location determined by an UE on-boardlocation module (e.g. GPS), or other location methods can be used suchas the LTE Positioning Protocol. (See e.g. 3GPP TS 36.355 specification,incorporated herein by reference in its entirety). In this case, thehandover module 360 causes the notification module 330 to generate theWLAN handover command message with the BSSID of the desired AP, andoptionally the security parameters of the WLAN AP.

To summarize the above, upon determining that a handover should beperformed, the handover module 360 causes the notification module 330 togenerate and transmit a WLAN handover command message to the UE 400 thatincludes: (1) AP ID; and (2) (Optionally) WLAN security parameters.

WLAN Handover

Once the UE 400 receives the WLAN handover command, the UE 400 attemptsto connect to the desired AP identified in the command. In doing so, theUE 400 tunes its radio 414 for WLAN to the frequency of the AP, andattempts to establish a connection with the AP. If the command includedsecurity information, the UE 400 can use the security information toexpedite authentication between the AP and the UE 400.

In an embodiment, the WLAN handover command can include more than onedesired AP for potential offload. In this scenario, the UE 400 can beconfigured to attempt to establish a connection with each of the APs inthe order that they are listed, until a successful connection isestablished. Whether the command includes one or multiple APs, if the UE400 has attempted to establish connection with all the listed APsunsuccessfully, then the UE 400 should re-establish connection with thebase station 300. This can be performed by following current LTE“re-establishment” procedures and defined in the 3GPP LTE specification,for example.

Message Size Reduction

Optionally, the base station 300 and the UE 400 can be configured tonotate listings of APs within any of their respective messages.Therefore, this method can be applied to any of the WLAN measurementconfiguration, WLAN measurement report, and WLAN handover commandmessages. As discussed above, one way to identify each of the APs inthese messages is to list their SSID or BSSIDs. However, theseidentifiers are relatively long in length (e.g., a typical SSID can be a31-octet string). Therefore, rather than identify each of the APs bytheir full string, each can be assigned a label of only a few bits. Thelabel can then be used to an access a pre-existing table available toboth the base station 300 and the UE 400, to identify the actual SSIDand BSS ID.

One method that is easily implementable is to label each of the APs bytheir position in the whitelist supplied in the WLAN measurementconfiguration message. For example, the first AP would be labeled 1, thesecond AP would be labeled 2, and so on. The number of bits used torepresent the labels can be static based on a maximum number of APs thatthe base station 300 anticipates finding at any UE location, staticbased on the maximum number of APs known to the base station 300, ordynamic based on the number of APs that are to be included within theWLAN measurement configuration message. Another method is to label eachof the APs by their position in the measurement report supplied in theWLAN measurement report message. Using this implementation, each APidentifier can be reduced from several bits in size to only a few,thereby substantially reducing message sizes, which results in manyfollowing benefits.

Exemplary Offloading Message Flows

Although each of the messaging steps has been described above in greatdetail, the flow of these steps in different configuration scenarios isdiscussed in greater detail below with respect to FIGS. 5-8. Forpurposes of discussion, it will be assumed that the offload measuringand decision-making is being done in an LTE network, and that theoffloading is being directed to a WLAN access point.

Discussed above were three scenarios that depended on the availabilityof WLAN interworking notification and UE notification. FIGS. 5-8illustrate these individual scenarios, as discussed below. In each ofFIGS. 5-7, the procedure begins with a few common steps that aredescribed first, and then not repeated for each of FIGS. 5-7. First, thebase station 300 (labeled “E-UTRAN”) transmits the WLAN InterworkingCapability Inquiry message to the UE 400 (510, 610, and 710) so as torequest UE device capabilities. In response, the UE 400 transmits theWLAN Interworking Capability Information message (520, 620, and 720)that details the UE's capabilities as they relate to UE notification,WLAN interworking notification, and others. Following the WLANInterworking Capability Information message, the base station 300transmits the WLAN Notification Configuration message (530).

WLAN Interworking Notification Allowed—UE Notification Allowed

FIG. 5 illustrates a flowchart diagram of a first exemplary handoverprocedure according to an embodiment in which the base stationidentifies both WLAN interworking notification and UE notification asbeing allowed. Therefore, in this scenario, the base station 300indicates in the WLAN Notification Configuration message that both WLANinterworking notification and UE notification are allowed. Further, theWLAN Notification Configuration message may also identify the triggersthat can be used by the UE 400.

The UE 400 receives the WLAN Notification Configuration message andconfigures its trigger monitoring module 440 to monitor the triggersdefined in the message. As part of the WLAN interworking notification,when the trigger monitoring module 440 detects that one of the definedtriggers has been met, the trigger monitoring module 440 can cause aWLAN Interworking Notification message (540) to be sent to the basestation 300 that includes a notification of the trigger that has beensatisfied. Optionally, the WLAN Interworking Notification message caninclude the location of the UE 400 by prompting the location module 430,and/or its accuracy. The location information can be used by the basestation when configuring the scan parameters of the UE 400.

The base station 300 then issues a WLAN measurement configurationmessage (550) that identifies one or more of WLAN channels to bescanned, an AP white/blacklist indicating which APs to report back tothe base station 300, and scan triggers, among others as describedabove. Upon the trigger being met, or some other condition, the UE 400performs a scan in accordance with the measurement configurations setforth in the WLAN measurement configuration message. Because UEnotification is enabled, the UE 400 then issues a WLAN measurementreport message (560) that includes a listing of APs that were scanned,and corresponding information of those APs, such as SSID, BSSID, signalstrength, BSS load, or others.

Using the information included within the WLAN measurement reportmessage, the base station 300 performs a handover determination. Upondetermining that a handover should be initiated, the base station 300transmits a handover command (570) that identifies one or more APs towhich the UE 400 should attempt to handover. Optionally, the basestation 300 can also provide security information of the APs.

After receiving the handover command, the UE 400 proceeds to attempt toestablish connection with each of the APs (580) identified in thecommand, in the order of their listing, until a successful connection isestablished. If security information was included in the command, the UE400 can utilize the information for authentication. If the UE 400 hastraversed the entire list of APs in the command without a successfulconnection, the UE 400 then attempts to re-establish with the basestation 300.

WLAN Interworking Notification Not Allowed—UE Notification Allowed

FIG. 6 illustrates a flowchart diagram of a second exemplary handoverprocedure according to an embodiment in which the base stationidentifies WLAN interworking notification as being allowed, UEnotification as being disallowed.

Therefore, following the WLAN Interworking Capability Informationmessage, the base station 300 transmits the WLAN NotificationConfiguration message (630) that indicates that the WLAN interworkingnotification is not allowed, and that the UE notification is allowed.Because WLAN interworking notification is not allowed, the UE 400 doesnot notify the base station 300 when a trigger has been met. Instead,the base station 300 follows up the WLAN Notification Configuration withthe WLAN measurement configuration message (640) identifying one or moreof WLAN channels to be scanned, an AP white/blacklist indicating whichAPs to report back to the base station 300, and scan triggers, amongothers as described above.

The UE 400 configures itself to scan in accordance with the procedureand/or parameters set forth in the WLAN measurement configurationmessage (discussed above). Because UE notification is allowed, the UE400 can scan and report scan results upon the detection of a triggerwithout additional communication with the base station. Upon performingits scan, the UE 400 issues the WLAN measurement report (650) to notifythe base station of the results of the scan.

The base station 300 makes a handover determination based on theinformation included in the WLAN measurement report and, if it decides ahandover is needed, transmits a handover command (660) to the UE 400,which causes the UE to initiate a handover (660).

WLAN Interworking Notification Not Allowed—UE Notification Not Allowed

FIG. 7 illustrates a flowchart diagram of a first exemplary handoverprocedure according to an embodiment in which the base stationidentifies both WLAN interworking notification and UE notification asnot being allowed.

Following the WLAN Interworking Capability Information message, the basestation 300 transmits the WLAN Notification Configuration message (730)that indicates that neither WLAN interworking notification or the UEnotification is allowed. As with above, because WLAN interworkingnotification is not allowed, the base station 300 follows up the WLANNotification Configuration with the WLAN measurement configurationmessage (740) setting forth the scan parameters. However, because UEnotification is also not allowed, the UE 400 only scans after receivinga notification from the base station 300 to do so. In other words, onlynetwork based events will trigger a scan. In an embodiment, the receiptof the WLAN measurement configuration message can be the trigger thatcauses the scan.

After performing its scan according to the WLAN measurementconfiguration message, the UE 400 replies with the WLAN measurementreport (750) that provides the base station 300 with the results of thescan. As with the above, the base station 300 then makes a handoverdetermination based on the information included in the WLAN measurementreport and, if it decides a handover is needed, transmits a handovercommand (760) to the UE 400, which causes the UE to initiate a handover(770).

Blind Handover

FIG. 8 illustrates a flowchart diagram of a blind handover procedurethat may be performed by the base station 300 and the UE 400.

In this scenario, the UE 400 may optionally provide the base station 300with a WLAN interworking notification message (810), perhaps requestinginterworking assistance and notifying the base station 300 of radioaccess technology (RAT) and network preferences. In any event, the basestation 300 independently determines that the UE 400 should handover toa WLAN AP, and thus transmits a handover command (820) to the UE thatincludes a listing of one or more APs and optionally their securityinformation. The UE 400 then attempts to handover (830) to the APs untila successful connection is established.

The framework described herein supports offloading procedures that canbe triggered either autonomously by the network or at the request of theuser. In other words, the framework supports both network-based triggerevents and user-based trigger events offload scenarios. This enables thebroadest coverage of wireless inter-system offload use cases.Additionally, after the base station 300 has made an offload decision,the system utilizes air-interface level enhancements for the cellularnetwork to gather knowledge of radio resources at the offload side. Thecellular network can make use of such information to efficientlycoordinate inter-system mobility so that the offload latency is reduced,overall system throughput is increased, and the user experience isimproved. Also, the proposed framework enables optimizations such aspre-authentication to be done at the cellular side and inter-system“blind handover” to further reduce the offload latency. Furtheradditional benefits may be achieved through the use of the disclosedcommon framework.

LTE Standard

In order to implement the above configurations, it may be advantageousto revise current standards in order to accommodate theseconfigurations, as described below. For example, it may be advantageousto alter and/or revise the LTE specification, as detailed below.

The message content, the triggers to the message and procedures to befollowed upon receiving the messages, as described herein, could bewritten into a future LTE standard, in order to ease implementation.However, it should be noted that the message content described hereinmay also be carried by modifying the existing RRC messages, e.g.RRCConnectionReconfiguration message, specified in 3GPP TS36.331.

In addition, a WLAN interworking entity in the cellular core networkcould be added. This entity may be responsible for coordinating networkbased triggers and providing the most relevant offload network discoveryand selection information in the WLAN measurement procedures. Thedetails of this WLAN interworking entity is described in detail in U.S.patent application Ser. No. 14/156,960; filed Jan. 16, 2014, Atty Dkt.No. 3875.7000001, entitled “Wireless Communication System UtilizingBroadcast-Based Blind Offloading,” which is incorporated herein byreference in its entirety.

Exemplary Computer System Implementation

It will be apparent to persons skilled in the relevant art(s) thatvarious elements and features of the present disclosure, as describedherein, can be implemented in hardware using analog and/or digitalcircuits, in software, through the execution of instructions by one ormore general purpose or special-purpose processors, or as a combinationof hardware and software.

The following description of a general purpose computer system isprovided for the sake of completeness. Embodiments of the presentdisclosure can be implemented in hardware, or as a combination ofsoftware and hardware. Consequently, embodiments of the disclosure maybe implemented in the environment of a computer system or otherprocessing system. An example of such a computer system 900 is shown inFIG. 9. One or more of the modules depicted in the previous figures canbe at least partially implemented on one or more distinct computersystems 900.

Computer system 900 includes one or more processors, such as processor904. Processor 904 can be a special purpose or a general purpose digitalsignal processor. Processor 904 is connected to a communicationinfrastructure 902 (for example, a bus or network). Various softwareimplementations are described in terms of this exemplary computersystem. After reading this description, it will become apparent to aperson skilled in the relevant art(s) how to implement the disclosureusing other computer systems and/or computer architectures.

Computer system 900 also includes a main memory 906, preferably randomaccess memory (RAM), and may also include a secondary memory 908.Secondary memory 908 may include, for example, a hard disk drive 910and/or a removable storage drive 912, representing a floppy disk drive,a magnetic tape drive, an optical disk drive, or the like. Removablestorage drive 912 reads from and/or writes to a removable storage unit916 in a well-known manner. Removable storage unit 916 represents afloppy disk, magnetic tape, optical disk, or the like, which is read byand written to by removable storage drive 912. As will be appreciated bypersons skilled in the relevant art(s), removable storage unit 916includes a computer usable storage medium having stored therein computersoftware and/or data.

In alternative implementations, secondary memory 908 may include othersimilar means for allowing computer programs or other instructions to beloaded into computer system 900. Such means may include, for example, aremovable storage unit 918 and an interface 914. Examples of such meansmay include a program cartridge and cartridge interface (such as thatfound in video game devices), a removable memory chip (such as an EPROM,or PROM) and associated socket, a thumb drive and USB port, and otherremovable storage units 918 and interfaces 914 which allow software anddata to be transferred from removable storage unit 918 to computersystem 900.

Computer system 900 may also include a communications interface 920.Communications interface 920 allows software and data to be transferredbetween computer system 900 and external devices. Examples ofcommunications interface 920 may include a modem, a network interface(such as an Ethernet card), a communications port, a PCMCIA slot andcard, etc. Software and data transferred via communications interface920 are in the form of signals which may be electronic, electromagnetic,optical, or other signals capable of being received by communicationsinterface 920. These signals are provided to communications interface920 via a communications path 922. Communications path 922 carriessignals and may be implemented using wire or cable, fiber optics, aphone line, a cellular phone link, an RF link and other communicationschannels.

As used herein, the terms “computer program medium” and “computerreadable medium” are used to generally refer to tangible storage mediasuch as removable storage units 916 and 918 or a hard disk installed inhard disk drive 910. These computer program products are means forproviding software to computer system 900.

Computer programs (also called computer control logic) are stored inmain memory 906 and/or secondary memory 908. Computer programs may alsobe received via communications interface 920. Such computer programs,when executed, enable the computer system 900 to implement the presentdisclosure as discussed herein. In particular, the computer programs,when executed, enable processor 904 to implement the processes of thepresent disclosure, such as any of the methods described herein.Accordingly, such computer programs represent controllers of thecomputer system 900. Where the disclosure is implemented using software,the software may be stored in a computer program product and loaded intocomputer system 900 using removable storage drive 912, interface 914, orcommunications interface 920.

In another embodiment, features of the disclosure are implementedprimarily in hardware using, for example, hardware components such asapplication-specific integrated circuits (ASICs) and gate arrays.Implementation of a hardware state machine so as to perform thefunctions described herein will also be apparent to persons skilled inthe relevant art(s).

CONCLUSION

The exemplary embodiments described herein are provided for illustrativepurposes, and are not limiting. Other exemplary embodiments arepossible, and modifications may be made to the exemplary embodimentswithin the spirit and scope of the disclosure.

It is to be appreciated that the Detailed Description section, and notthe Abstract section, is intended to be used to interpret the claims.The Abstract section may set forth one or more, but not all exemplaryembodiments, of the disclosure, and thus, are not intended to limit thedisclosure and the appended claims in any way.

The disclosure has been described above with the aid of functionalbuilding blocks illustrating the implementation of specified functionsand relationships thereof. The boundaries of these functional buildingblocks have been arbitrarily defined herein for the convenience of thedescription. Alternate boundaries may be defined so long as thespecified functions and relationships thereof are appropriatelyperformed.

It will be apparent to those skilled in the relevant art(s) that variouschanges in form and detail can be made therein without departing fromthe spirit and scope of the disclosure. Thus the disclosure should notbe limited by any of the above-described exemplary embodiments. Further,the claims should be defined in accordance with their recited elementsand their equivalents.

What is claimed is:
 1. A base station, comprising: a radio configured tocommunicate with a user equipment served by the base station; and aprocessor and/or one or more circuits, coupled to the radio, configuredto: acquire device capabilities of the user equipment; transmitnotification configuration parameters to the user equipment based on thedevice capabilities; and receive a measurement report from the userequipment providing results of an environment scan performed by the userequipment, and determine whether to instruct the user equipment tohandover communication to a wireless access point based on the resultsof the environment scan, the wireless access point using a differentradio access technology than the base station.
 2. The base station ofclaim 1, wherein the device capabilities identify whether the userequipment is capable of performing trigger notification in which theuser equipment notifies the base station of the occurrence of a firsttrigger, and wherein the device capabilities include whether the userequipment is capable of performing interworking notification in whichthe user equipment performs the environment scan and reports the resultsof the environment scan to the base station upon detecting theoccurrence of a second trigger.
 3. The base station of claim 1, whereinthe processor and/or the one or more circuits is further configured to:define a trigger that will cause the user equipment to take apredetermined action when the trigger is satisfied, wherein thenotification configuration parameters include the trigger.
 4. The basestation of claim 3, wherein the trigger corresponds to a proposedtrigger that the base station received from the user equipment.
 5. Thebase station of claim 1, wherein the processor and/or the one or morecircuits is further configured to transmit measurement configurationparameters to the user equipment for configuring the environment scan.6. The base station of claim 5, wherein the processor and/or the one ormore circuits is further configured to transmit the measurementconfiguration parameters in response to receiving an interworkingnotification message from the user equipment indicating that apredetermined trigger has been satisfied.
 7. The base station of claim5, further comprising: a storage device configured to store a listing ofat least one known wireless access point, wherein the measurementconfiguration parameters identify the at least one known wireless accesspoint as a target for scanning during the environment scan.
 8. The basestation of claim 5, wherein the measurement configuration parametersfurther include a report trigger that, when satisfied, causes the userequipment to perform the environment scan and report the results of theenvironment scan to the base station.
 9. A user equipment, comprising: afirst radio configured to communicate with a base station serving theuser equipment; a second radio configured to communicate with one ormore wireless access points that use a different radio technology thanthe base station; and a processor and/or one or more circuits,configured to: transmit a description of device capabilities of the userequipment to the base station using the first radio; monitor a trigger,the trigger being defined by the base station or based on the devicecapabilities; and perform an environment scan using the second radioupon the detection of the trigger, and report results of the environmentscan to the base station using the first radio.
 10. The user equipmentof claim 9, wherein the processor and/or the one or more circuits isfurther configured to define a proposed trigger for proposing to thebase station, the proposed trigger being transmitted together with thedescription of device capabilities to the base station.
 11. The userequipment of claim 9, wherein the processor and/or the one or morecircuits is further configured to, when the trigger has been satisfied,transmit an interworking notification message to the base station usingthe first radio notifying the base station of the satisfied trigger. 12.The user equipment of claim 9, wherein the processor and/or the one ormore circuits is further configured to perform the environment scanaccording to scan parameters received from the base station.
 13. Theuser equipment of claim 12, wherein the scan parameters identify aparticular wireless access point of the one or more wireless accesspoints, and the processor and/or the one or more circuits is furtherconfigured to scan the particular wireless access point as part of theenvironment scan.
 14. The user equipment of claim 9, wherein theprocessor and/or the one or more circuits is further configured toreceive a handover command from the base station using the first radio,the handover command identifying a selected wireless access point fromthe one or more wireless access points, and to perform a handoverprocedure to the selected wireless access point using the second radio.15. The user equipment of claim 14, wherein the processor and/or the oneor more circuits is further configured to use security information ofthe selected wireless access point provided in the handover commandduring the handover procedure.
 16. A method of performing handoverdecisions by a base station for a user equipment that is served by thebase station, the method comprising: requesting device capabilities ofthe user equipment; receiving the device capabilities from the userequipment; transmitting notification configuration parameters to theuser equipment based on the device capabilities, the notificationconfiguration parameters indicating whether a first notificationprocedure is to be used and whether a second notification procedure isto be used; receiving results of an environment scan performed by theuser equipment, the results including a listing of detected wirelessaccess points and at least one connection parameter of each of thedetected wireless access points; determining, from the results of theenvironment scan, whether the user equipment is to perform a handoverprocedure to one of the detected wireless access points; andtransmitting a handover command to the user equipment when it isdetermined that the user equipment should perform the handoverprocedure.
 17. The method of claim 16, further comprising: transmitting,when the notification configuration parameters indicate that the firstnotification procedure is to be used, a first trigger to be used withthe first notification procedure; and transmitting, when thenotification configuration parameters indicate that the secondnotification procedure is to be used, a second trigger to be used withthe second notification procedure.
 18. The method of claim 17, furthercomprising: acquiring security information of the one of the detectedwireless access points through a network backhaul, wherein the handovercommand includes the security information.
 19. The method of claim 16,further comprising transmitting measurement configuration parameters forconfiguring the environment scan, the measurement configurationparameters including an approved list of wireless access points, whereinthe listing of the detected wireless access points included within theresults of the environment scan is limited to wireless access pointsidentified in the approved list.
 20. The method of claim 19, wherein theresults of the environment scan identify the detected wireless accesspoints by their corresponding numerical positions in the approved listof wireless access points.